There is nothing wrong with using the vaccum (as long as you don't care about the gunk that will get stuck in it)but you still have to wash and scrub the cage. I like to clean out the litter and food bits every day and I give the cage a good scrubbing once or twice a week or when ever they have an accident and miss the litter box. Welcome to Paw Talk and the wonderful world of ferrets! I have two myself and I plan on adopting my third in three weeks or as soon as my application is accepted.
I smile because I have absolutely no idea what's going on!